The present invention relates to a heating system and, more particularly, the invention relates to a mobile heating system which is uniquely adapted for use at construction sites and/or for various ground-thawing purposes.
In the northern climates there are a great many uses for a portable or mobile heating system, particularly in the construction industry, but also in the maintenance and correction of ground-freezing problems relating to preexisting structures. A common problem in the northern climate is the problem of frozen underground water and/or sewer pipes. This problem is caused by a combination of factors; in some cases the underground pipes are laid too close to the surface, and in other cases a severe cold spell without adequate snow cover causes ground freezing to unexpected depth. One general type of solution to this problem is to obtain access into the pipe and/or conduit which is frozen, and inject heated liquid into the conduit until the frozen portion becomes dislodged of ice. Another general type of approach which has been used, particularly in the case of metal underground pipes, is to apply a very high electrical current to the metal pipe casing, thereby heating it to a temperature which causes the interior to become thawed. A third general type of solution to this problem has been to insert heating pipes into the ground itself, and thaw the ground surrounding the pipe, thereby thawing the pipe. The present invention is directed to this third type of solution, at least with respect to the problem of thawing underground pipes.
A further problem exists in connection with outdoor construction projects in cold climates. For example, construction work such as bricklaying is severely hampered in cold weather, not only because the concrete tends to be difficult to maintain in usable form, but also because the sand mixtures and the bricks themselves tend to become frozen. The optimum temperature for laying brick or block materials is in the range of 40.degree.-45.degree. Fahrenheit. If the temperature drops below this range, the mortar used to bond the bricks and/or blocks will not properly adhere to the materials, leading to a weakened construction. In such situations, it would be helpful to heat up the temperature of such construction materials so as to improve the overall quality and efficiency of the finished construction project. The present invention is also useful on construction projects for heating construction materials in preparation of use.